1. Field
The present invention relates to a method for bonding honeycomb cores together using a syntactic core and non-foaming film adhesive.
2. Related Art
Honeycomb cores made of composite material, metals, or any combination thereof are often used in the construction of aircraft parts. For example, honeycomb cores are used to make acoustic panels in a nacelle for attenuating engine noise. Because of the large size of aircraft acoustic panels, it is usually necessary to splice multiple honeycomb cores together to form a single acoustic panel or core structure. Furthermore, to create acoustic panels of a desired shape and contour, a plurality of honeycomb cores are often spliced together.
Prior art methods of splicing honeycomb cores use various foam adhesives to bond the honeycomb cores together. However, the foam adhesive can overexpand at various locations during curing or heating, causing gaps between the adhesive and/or the honeycomb cores. This overexpansion can necessitate rework and repair of the spliced core assemblies, which can increase labor costs.
Furthermore, the thickness of the bondline formed by the foam adhesive adversely affects the acoustic performance of the acoustic panel. Sound waves bounce off of this bondline back into the nacelle and then out through the inlet, instead of being absorbed by the acoustic panel.
Accordingly, there is a need for an improved method for splicing honeycomb core together.